(38e) Biodiesel Production without Glycerol Byproduct: Dimethyl Carbonate As Replacement for Methanol

Biodiesel Production without Glycerol Byproduct: Dimethyl Carbonate as Replacement for Methanol

Tamara Frydson and Tracy J. Benson

Dan F Smith Department of Chemical Engineering, PO Box 10053, Lamar University, Beaumont, TX 77710

Currently, biodiesel is produced as a supplement for petroleum diesel and is comprised of a mixture of fatty acid methyl esters (FAME's).  However, glycerol, a low-value byproduct, is also produced.  The downstream processing required to separate glycerol from the biodiesel product requires substantial amounts of water, energy, equipment, and process unit operations.  This work reports on a biofuel, analogous to biodiesel, that can be produced by reacting lipid oils with dimethyl carbonate (DMC), instead of methanol. The DMC reaction produces 2 FAMEs and 1 fatty acid glycerol carbonate (FAGC) for every triglyceride molecule converted.  This reaction scenario generates a more desirable product, without the glycerol byproduct, at lower production costs.

Experiments were conducted using canola oil, DMC, and triazabicyclodecene catalyst.  Products were first identified using GC/MS and were found to be fatty acid methyl esters (FAMEs) and fatty acid glycerol carbonates (FAGCs).  The FAGCs are miscible with FAMEs, and are, therefore, usable as a fuel.  The produced biofuel passed the ASTM D6751 standard for biodiesel. Complete reaction details, including kinetic results, and process modeling using Aspen Plus simulator will be presented.